(1) Field Of The Invention
The present invention relates to sealing assemblies used on rotating shafts and more particularly, relates to an axially pressure balanced floating seal system used on a drive shaft.
(2) Description Of The Prior Art
O-ring seals are commonly used to seal rotating shafts used in vehicles or machinery. For example, in an existing torpedo tail cone assembly 10, FIG. 1, the drive shaft 12 of the torpedo is typically sealed with an O-ring seal system having a seal housing 14 and an O-ring seal 15 within a groove in an internal annular surface of the housing 14. The seal housing 14 is located within the tail cone housing 16 near the bearing 18. When the torpedoes have stable and concentric shaft bearing mounts relative to the seal, non-floating seal housings can be used, and these housings will still maintain reasonable clearance to prevent rubbing between the shaft 12 and the seal housing 14. Larger shafts that are mounted soft enough to move or float relative to the seal housing require floating seal housings. The floating seal housing moves with the drive shaft 12 generally in a radial direction as indicated by arrow 2 maintaining clearance of the shaft 12 and preventing the shaft 12 from rubbing against the seal housing 14.
In order to allow greater torpedo reliability and operations at depth, replacement of the prior art seal described above was proposed. If a larger envelope is available for a seal, an axially pressure balanced floating seal system could be implemented to allow radial movement of the drive shaft. The seal should also be operative at greater pressures while the drive shaft is rotating at operational speeds.
One object of the present invention is a high pressure, dynamic seal system that moves radially with the drive shaft at all operating pressures.
Another object of the present invention is a high pressure seal system fitting that can be used in current systems with only minor modifications.
A further object of the present invention is a reliable high pressure seal system in which the sealing members are effectively lubricated.
Accordingly, the present invention provides an axially pressure balanced floating seal system positioned within a structure about a rotating shaft. The floating seal system has a cylindrical outer seal housing with a cylindrical internal recessed region formed therein. A retaining flange extends radially from the housing into the internal recessed region. A cylindrical inner seal housing is positioned within the internal recessed region. The inner seal housing has an annular internal surface for accommodating the rotating shaft. Two sealing member retaining grooves are provided in the annular internal surface and a lubricant recess or oil gallery is formed between the two grooves. An intermediate seal is retained on the inner seal housing forward face between the inner seal housing and the outer seal housing at the retaining flange. Sealing members are positioned in the sealing member retaining grooves at substantially the same radius as the intermediate seal.